Metal-bending brake



July 23, 1929 J. KRUl-:GER 1,721,698

METAL BENDING BRAKE Filed Feb. 14. 1927 3 Sheets-Sheet l rllllh'lm ilvmmimm, sigb MHZ J. KRUEGER METAL BENDING BRAKE 3 Sheets-Sheet 2 Filed Feb. 14, 1927 July 23, 1929.

July 23, 1929. J. KRUEGER METAL BENDING BRAKE Filed Feb. 14, 1927 3 Sheets-Sheet web.

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I N V EN TOR. ../'an Kragen A TTORN E Y.

Patented July 23, 1929.

UNITED STATES JOHN KRUEGER, 0F MILWAUKEE, WISCONSIN.

METAL-BENDING BRAKE.

Application filed February 14, 1927. Serial No. 168,159.

This invention relates to those appliances commercially known as bending brakes, commonly employed in the forming of sheet metal structures.

rl`he object of the invention here considered provides several advantages that are absent from the mechanical brakes now extant. This invention presents a structure whose design offers an open end brake that is free from certain adjuncts which obstruct the machine ends so that blanks, to be formed, are restricted to lie inside the ends, necessitating excess operations, in order to complete certain formations. Another feature offers a varying means whereby several positions for a novel clamping arrangement, functions also, as the bending shoulders or edges, about which the sheet metal is wiped, provides an advantage of unquestionable value that lends a machine of this kind for the accomplishing of a greater f'ariety of work not readily feasible, and, in several instances impossible with the existing design of brakes. The ready and easy adjustment for attaining a greater assortment of bends and varied contours, present a novel departure that is attained simply enough to be clearly understood by that class of labor employed in this field. Further, the necessary balancing, here required, is removed to where same does not form an outside obstruction in quarters where oor space is valuable, this and the accuracy of the inventions alignable parts which assures perfect and reliable performance that will conlpeusate for an operators lack of skill; and. due to the simplicity and easy handling of heavy parts, will extend the machines uninterrupted periods of usefulness. Also, the general design, here considered, presents itself as an economical manufacturing proposition for those interested in the production and marketing of this class of mechanical equipment.

Other advantages will be noted in thel particular description, which refers to the accompanying drawings, and pointed out in the apiliended claims, all of which comprise this application.

The several views that illustrate this invention are here indexed, as follows:

Fig. l is a condensed front elevation.

Fig. 2 is an end elevation.

Fig. 3 is a section on line 3 3 Fig. 1..

Fig. 4 is an inner face elevation of the eccentric group.

F ig. 5 is a top plan view of Fig. 4.

Fig. 6' is a perspective view of a clamping unit.

Fi g. 7 is a perspective view of the shoulder blocks. Y

Fig. 8 is a perspective view of a blank formable on this brake.

Similar characters of reference apply to like parts throughout the several views.

Referring more particularly to the drawings the structure will be understood as comprising: a general framework F, of rectangular outline, that provides a stationary base which supports all the operative mechanism here considered. The saidv base is the usual bench height in keeping with a standing adult operator whose position is at the front, or, left side of Fig. 2. The structure seen in Fig. 2 is opposedly reproduced at the other machine end. Fig. l is curtailed by being broken off away from the medial center about which the machine is symmetrically designed. The varying aspects of the machine parts, when in operation, are indicated by dotted lines in Fig. 3. A bed plate 1 offers a table-top for the framework that partially covers the frameworks plan area; this bed plate is disposed to present its front odge coincident with the vertical plane of a hinging axis forwardly located. A bending apron 2 normally hangs against the front of the machine and offers end portions that are free of all hinge encumbrances; its upper edge is accurately established by introducing an inlaid hardened steel bar 2"- so that the exposed longitudinal corner 2b will coincide with the axial hinge center; the upper edge of the bar 2 is flush with the upper face of an angle element 2c, said angle being fixed as a part of the apron 2 to function as a surface that wipes over the sheet stock in process of bending same when the apron is swung upward for this purpose. The operation of the apron 2 is performed by the handles shown for swinging this element about the axis of forward hinge sets which latter vexerted at their projecting ledges.

are accurately aligned to allow of attaining an absolutely perfect and true bending line at the bars corner 2b. The hinging elements are located to allow the apron ends to extend beyond them, thereby gaining a free hinge-crack at both sides of the brake. A hinge set comprises an apron hinge leaf 3, bed plate leaves 1, and the pintle 5; loops 4f are accurately reamed to receive the pintle 5, the latter being set-screwed to be fixed in a loop 3 of the apron leaf 3. The hinge leaves 3 and fl provide terminal toes 3 and Il for the location of set-screws used to attain a positive alignment of the apron assembly, and other elements, with the fundamental bending line forming the aforesaid hinge axis, and for maintaining this alignment by the set-screw means for guarding against a departure therefrom due to any possible loosening caused by the machines wear and tear. The apron assembly is subjected to heavy strains that might distort it; these strains are intended to be resisted by reinforcing the apron plate 2 with a stiifening member 6 against which abuts a shoulder 7 fashioned on the hinge leaves 3. VThe apron assembly is counterbalanced in a manner that provides an arm 8 rigidly part of the said apron, and located to terminate with a selected weight 9 that is normally at rest behind the machine, and adapted to swing, with the apron, through an arc that avoids the forward portions of the framework F,

which latter has an open rearward area between its ends; thus preventing a heavy swinging counterbalance from being an Vobstruction beyond `the machine ends, and the avoiding of interference with other operative parts. i

The bed plate 1 is somewhat below the hinge axis while offering its forward edge to lie adjacent the vertical plane of this axis; the definite axial line is approached by the outer longitudinal corners of base blocks 10 that are machined to offer forwardly projecting ledges 10a, the said blocks are fastened to the bed plate 1 in abutting relationship to an undercut shoulder plate 11 whose angular edge corresponds to the rearward slope of the base blocks for the resisting of any tilting tendency in the blocks when pressure is The plate 11 also accommodates other base blocks 12, similar to the blocks 10, except that the former have no projecting ledges. The simpler bloc is are chosen in lieu of, or, along with blocks 1() when a blank is to receive opposing flanges that are formed by inverting already formed flanges into the hinge-crack and against the plain face of a block 12, thereby allowing` the apron to wipe up a flange without disturbing the rest of the blank.

Situated longitudinally above the bed plate 1 is a prismatically formed assembly T, maintained in rockable relationship to the frame F by means of a pivoting shaft 13. Theassembly T is constructed of several elements comprising, end castings that form triangular trusses 14- which are held in spaced relationship by a bottom plate 15, a front plate 16, and further stiffened to resist stresses with additional angle-iron. members. This assembly may be riveted or welded together to form a vertically integral whole for resisting, without distortion, the attending strains to which the unit T is subjected. The plate 15 offers a forwardly disposed ledge, or cave 17 by virtue of the plate 16 terminating` above the said eave thereby providing necessary hand room for attaching series of clamping units to be shortly described. The shift 13 extends freely through sleeve-like bearings 18 bored in the trusses 111, to where it is keyed in gib-blocks 19, which latter slide adjustably in upstanding supporting castings 2O or bracket members that are rigidly attached to the outer vertical faces of inwardly turned, angles a that form lateral end members of the frame F and which offer their horizontal faces for supporting elements yet to be described. The gib-blocks 19 are accurately adjustable by screws in a manner well known for bearings of this kind.

Upon the under-side of the plate 15 is located a longitudinally 1abbeted bar 21 that offers a groove for receiving the opposedly rabbeted ends of clamping units 2Q, which latter may be of various widths while remaining uniform in the lateral aspect. These units are downwardly curved at their forward extensions to present reinforced edges upon or over the base blocks 10 or 12, and are permitted to have their aforesaid edges adjusted for coinciding with: the before-mentioned axial line, the vertical plane of said axis, or any degree of parallel departure therefrom.v The retention of these units in any selection of abutting, or, separated relationship is attained by means of their rearward edges registering with the rabbeted bar 21, and again, by forwardly located clips 22 which overlie the cave 17 to which latter the units are secured by hand-screws 22". The said units Q2, secured as described, become rigid elements of the shiftable assembly T and roch with said assembly about the nonrotating shaft 13.

Therequired oscillation of the assembly T is attained through an eccentric chocking means affected by the operator. This means converts the shaft 13 into a fulcrum element for said assembly. The angles a offer their horizontal flanges a as a base for a bearing 23 in which is a fixed stud 24 and about which rotates an eccentrically mounted disc 25, under the influence of a forwardly extended lever 26, lying within convenient reach of an operator. The said disc is designed to provide an. integral bearing 27 inwardly disposed to support a roller 28 in the vertical plane of the end truss casting 14 and beneath the bottom plate 15. The differences in gauge thicknesses occuring in sheet metal is compensated for by employing a wedgeshaped wearing plate 29 which may be adjustable through having a screw 30 rotat-` ably lodged in the truss 14, leaving a threaded end 31 as an integral part of the slidable plate 29 for getting a precise effect with the eccentric tilting means. The disc 25 offers a face 25 that may be toothed to accommodate a pawl 32, mounted upon the truss 14, which lodges in teeth formed selectively, if at all, in the face 25'; one such being shown in Fig. 2. The remarked differences in metal, which require the pawl precision, are seldom encountered. There is always an appreciable spring-like action residing in the clamps 22 to compensate for other than wide departures in the standard gauges. The discs dead-center effect is over av generous area, so that the checking effect of the eccentric takes care of, effectively, all gauges of metal intended for this kind of brake. However, the pawl adaptation has a desirable function to oller at times. The foregoing description will be understood to equally apply to the opposed and similar arrangement at the other machine end.

Operation of the brake is as follows: The hand lever 26 is raised and the blank (so labeled on the drawings) is slid over the base blocks 10 to where its bending markings agree with the corner edge 2b, the said lever is pulled down to chock up the rear of the assembly T which action also brings down the clamping units 22 upon the blank, pinch- 'ing it between the said units and the base blocks. The apron is rocked upwardly until that portion of the blank extending beyond the units is bent as desired. The ends of the brake are open to allow the blank to be passed beyond the bed plate area when it is required that flanges be formed on a blank such as shown in Fig. 8; the said figure illustrating a completed blank that is not attainable on existing brakes. The blocks l() are employed where upward flanges are made in the blank, these blocks may be continuous bars between the hinge sets, as may also obtain with the blocks 12, or, both forms of blocks may be alternately employed for getting upward and downwardly directed flanges on a blank. The hinge crack between the blocks 12 and the apron plate permits flanges to be downwardly disposed while upwardly bent portions are being formed. The offsetting' of the clamping units22 permit of getting a variety of radii. The low plane of the bed plate, and the arching upward of the clamping units permit blanks with central formations to be moved about in this machine and readily removed therefrom by virtue of the provision at the eccentric means which allows the dise to be rotated to where the clamps are raised far enough to allow the insertion or removal of any reasonably shaped sheet metal part.

Having described the invention what is claimed and desired for protecting by Letters Patent isz- 1. A bending and forming brake having, a stationary framework, a pivotcd rockable assembly laterally adjustable, a bed plate, bracket members upwardly extended from said framework for offering slidable support for the said assembly, said members positioned to offer unobstructed bed plate corners before them for permitting workedupon material to overlie said corners.

2. A bending and forming brake having, a bed plate, an apron member, hinge elements connecting said bed plate and said member, bracket members at the cndwise limits of said bed plate, the said plate extended before the brackets aforesaid to dispose its forward edge .longitudinally between and beyond the hinge elements and spacedly adjacent a vertical plane that includes the hinge elements axis.

3. A bending and forming brake having, a stationary framework, a bed plate, end brackets rigidly fixed to said framework intermediate the front and back of the said brake, said fixed location determined to flank the rearward edges of the aforesaid bed plate.

4. A bending and forming brake as recited in claim. 3 having, a tiltable superposed structure, a pivotal shaft for said structure, slidable bearings for said shaft, said bearings adjustable in the end brackets for selectively positioning the aforesaid structure.

5. A bending and forming brake having; a stationary framework; a rockable superstructure including a pivoting shaft; slidable bearings for said shaft; opposed bracket elements; said superstructure pivoted by said shaft forward of its longitudinal center of gravity; said bearings adjustable in said bracket elements; and means for attaining adjustment of said bearings along a horizontal plane above the base of said rockable superstructure, for retaining said adjustment, or, for allowing unrestricted freedom to the bearings in the aforesaid brackets.

6. A bending and forming brake having, a bed plate offering a forward edge, a pivotally mounted superstructure, a pivoting shaft continuous above and beyond the said bed plate for for supporting the said superstructure, journaling means for said shaft slidably locatable. said means shiftable for disposing the shafts axial center transversely above` the said forward edge to increase or decrease the distance between the said axial center and the forward edge of the bed plate aforesaid.

.7. A bending and forming brake having, a stationary framework, a bed plate, a rockable assembly superposed above the said bed plate, a supporting shaft pivotally a part of the said assembly, reciprocating means located at the shaft ends to allow a change in the aforesaid assemblys transverse position over the bed plate, tilting means stationary on said framework rearward of the aforesaid shaft, a rotative support for the said assembly offered by the tilting means, and a chocking element arranged to co-aet with the said rotative support.

8. A bending and forming brake having; a bed plate; a pivoted superstructure slidably, rockably, and tractionably supported over said bed plate; said plate offering a fixed forward edge; jonrnalling means, beyond the aforesaid superstructure, for allowing` transverse reciprocative adjustment of the supersruotare across a horizontal plane; precision means for affecting the said journalling means in order to maintain a parallel or non-parallel relationship between the superstructure and the edgeV aforesaid, said precision means designed to be removable for allo Ying said journalling means full freedom within the slidable limits. f

9. A bending and forming brake having, a rockable superstructure, said superstructure offering a forwardly disposed longitudinal cave element, a plurality oflaterally disposed clamping units positionable along said eave, means adapted for iiXedly arresting said units on said cave in abutting or separated relationship, a rabbeted bar beneath the superstructure and attached thereto, said bar interlockingly receiving the rearwardly projected ends of the aforesaid units.

l0. A bending` Vand forming brake having; upper clamping units, interchangeable bed blocks providing a work-plane opposed to said units; a forwardly disposed hinged apron; the said blocks and said units capable of being located coincident to the hinge axis of the aforesaid apron, or, noticeably removed from said axis.

lll. A bending and forming brake having, a stationary framework, a bed plate, a rockable superstructure, plural and selective blocks offering a work plane, clamping units opposed to said plane, said units forwardly extended from the said superstructure, a forwardly hinged apron member offering a reinforced bending` edge coincident with its hinge axis, pivoting means supported by the said framework for allowing the superstructure to rock about a transversely shiftable axis, said means allowing a varied selection for determining a clamping action with the units aforesaid to grip material lying upon the said work-plane before affecting said material with the apron member.

1Q. A bending and forming brake having, a stationary framework, a rockable assembly slidably and adjustably pivoted with respect to the stationary framework, eccentric means intermediate the said assembly and the framework aforesaid, said means positioneisd opposedly at either end of the framework and rearwardly of the axial line of 'the as- 'semblys adjustable pivot.

13. A bending` and forming brake having, an adjustably pivoted assembly; rearwardly located eccentric tilting means beneath said assembly, a pivoting shaft forwarsflly of said means, said shaft providing an adjustable fulcrum for the rearwardly positioned eccentric tilting means` lfl. A bending and forming brake having, rearwardly positioned eccentrics, forwardly extending levers controlling said eccentrics, an oscillatory assembly rocked by said eecentrics, wedge-shaped locking means upon the assembly. aforesaid, said means adapted to chock the aforesaid eccentrics in opposition to the said levers.

l5. A bending'and forming brake having, a stationary framework, eccentric means comprising dise-like elements, bearing means attached to said framework for jonrnalling said elements, a rockrble assembly, superposed above the framework a roller means inwardly and eccentrically projecting from the elements aforesaid and supporting the roekable assembly, forwardly directed levers lined to said elements said levers adapted to swing in vertical planes beyond the area of the aforesaid framework.

16. A bending and forming brake having, adjustable stock-supporting base blocks, superposed stock clamping units, a forward apron hinged to offer a constant edge longitudinally coincident with its hinge axis, said apron reinforced to provide a replaceable stock-wiping face said face being disposed in a horizontal plane coincident with the separated stock-supporting plane of the adjustable blocks, said face radially constrained to wipe upward stock projected beyond the aforesaid clamping units.

il. A bending and forming brake having, a stationary framework, an apron element forwardly hinged and balanced to normally hang spacedly parallel to the stationary framework, counterweight means integrally partof the apron structure, said means allowing the apron element to normally retain a vertical position, the counterweight means aforesaid comprising an inverted arcuate arm, said arm arranged to normally lie within the confines of the aforesaid framework.

18. A bending and forming brake having, plural hinge leaves, an apron plate sup- `ported by said plural hinge leaves, said leaves offering L-shaped toes, set screws threaded through said toes, said screws shouldering against said plate, said plate having an uppcr reinforced true edge the aforesaid set screws producing coincidence between the true edge aforesaid and the positive axial center of the hinge leaves and for maintaining said coincidence.

19. A bending and forming'brake having, an adjustable apron plate, hinge sets supporting said plate, superposed clamping units, varying shaped base blocks offering a continuous edge coincident with the axial center line of the said hinge sets, said base blocks arranged to dispose Athemselves adjustably beneath the opposing forward edges of the said clamping units. l

20. A bending and forming brake having, a framework supporting a base-block-edged bed pla-te, liing'e members offering horizontal leaves provided with downward toes attached to said bed plate, adjusting screwsI piercing the toes, said screws abutting said bed plate for aligning and retaining the base-block edge coincident to the aforesaid members axial center.

2l. A bending and forming brake having, base blocks, a rockable assembly, clamping units opposed'to said base blocks, eccentric chocking elements for determining the rockable limits of said assembly, inclined wedge plates intermediate the rockable assembly and said eccentric elements, and adjust-able means on the rockable assembly for positioning said wedge plates to assure a precise and positive grip upon a material-sheet introduced between the clamping units aforesaid and the said base blocks.

22. A beiiding'and forming brake having, forwardly ledged base blocks, downwardly curved clamping units providing gripping edges selectively locatable upon the upper plane of the base blocks, a bed plate member beneath the upper plane of the blocks aforesaid, the said ledges being arranged to overhang the forward edge of the aforesaid bed plate.

23. A bending and forming brake having, a bed plate, a changeable forward continuous bordel on said bed plate, an apron portion hingedly connected to said bed plate to offer a spaced or abutting relationship to said forward border between and beyond the hinge connections, and means whereby the said forward border and apron relationship may be alternately abutting or spaced.

24. A bending and forming brake having, a material-supporting stationary framework, a rockable and reciproca-table assembly adjustable over said stationary framework, clamping units selectively locatable upon and extendinff forwardly beyond said assembly, oscillataile discs eccentricallymounted on said framework, ether eccentric means, on

said discs offering cam elements, said cam elements allowing an unlimited choice of clamping relationships to obtain between the aforesaid units and the material-supporting framework.

25. In a bending and forming brake the combination of; a framework presenting a. table member having a partially completed top plate; a forwardly disposed apron member hinged to said plate and adapted to norinallv hang adjacently parallel to the front of the framework aforesaid; an inverted arcuate arm connected to said apron and extended rearwardly; and an apronbalancing weight on said arm adapted to lie behind, above, and within the longitudinal limits of said plate when at rest.

26. In a bending and forming brake the combination of a table framework having upstandiiig end supports intermediate its forward and rearward sides, a superposed assembly fully extending along and above the said framework and between the said supports; a longitudinal shaft member pivotally and slidably attaching the said assembly to the said supports at a point forwardly and below the said assemblys longitudinal center of gravity, and eccentric means behind the aforesaid supports for opposing the downward tendencyv of the unbalanced assembly.

27. In a bending and forming brake the combination as recited in claim 26 having, lever means beyond the framework and around the upstanding supports to function as manual controls adjacent the framework front, said levers affecting the eccentric means to pivotally position the overlianging assembly.

28. A bending and forming bi'ake having; an element providing a work-clamping plane surface; forwardly extended operating levers pivoted below said surface for vertical swinging; said levers effective for clamping stock without offering themselves as obstacles in the plane of said surface; and means whereby said-levers may be swung below the plane of said surface to effectively clamp the stock aforesaid 29. A bending and forming brake having, continuous and parallel ledge and slot means, clamping units of varying widths, said units, removably and slidably depended from said means in selectively abutting or separated relationships, downwardly curved gripping jaws, said jaws projecting from integral horizontal body portions, a rabbeted shoulder terminating the said body portion registering with the said slot, a recess located at the root of the curved jaw, and means co-acting with said recess and said ledge for maintaininor the units in fixed relationship along the afresaid means.

30. A bending' and formin brake havin n stata-mary framework, a pivetd rockab e UlA assembly, eccentric means located upon said framework and beneath said assembly for tiltingvthe aforesaid assembly to a workclamping position, an integral disc portion of the eccentric means disposed beside the said assembly, a pawl element carried by said assembly and pivoted thereto for swinging in the vertical plane of the said disc portion, and abutment means upon the disc portion to co-act with the aforesaid paWl for locking the said assembly in its Workclamping position.

y 3l. A. bending and forming brake having; ,a framework assembly su'ppporting a bed plate; an apron member; hinge elements connectingsaid bed plate and said apron; removable blocks attached to said bed plate offeringi bending edges coincident With, or, adjacently parallel to the axial center o the hinge connected apron; said blocks providing aligned and separated Work surfaces; intermediate Work surfaces, limited by the elements aforesaid7 lying,` between endivise block sets; said endWise block sets forming terminal Work surfaces that are free ended over the forward corners of the aforesaid bed plate.

In testimony of which I hereunto atlix my signature.

JOHN KRUEGER. 

